简介 |
An optical waveguide includes a first cladding layer made of glass material, a core made of glass material on the first cladding layer, and a second cladding layer covering the core and made of glass material including at least one of alkali element, alkali-earth element, and rare-earth element. The first cladding layer has a first softening temperature and a first refraction index. The core has a second refraction index larger than the first refraction index. The second cladding layer has a second softening temperature lower than the first softening temperature, and has a third refraction index smaller than the second refraction index. The optical waveguide is manufactured at high productivity since the second cladding layer does not deform. |